See it here

Now, my grandfather was 85% deaf by the time I was 20.  We got him headphones, but even then it still shook the house with how loud it needed to be.

Special headphones are not needed if you have proper hearing aids these days.  Yet there is no mention of hearing aids, just his very expensive headphones.

I remain highly skeptical of Daggy’s claims.  I’m 40% deaf in my right ear, but just fine in my left ear.  That’s called unilateral deafness.  And while that is nothing compared to 85%, it is still enough to make for a few problems.  It cuts off the high end for me and makes male voices easy to understand and women’s more difficult.  Yes, I have sexist hearing.